TW202111379A - Projection lens and projector - Google Patents

Abstract

A projection lens including a first lens, a second lens, an aperture stop, a third lens, a fourth lens, a fifth lens, a sixth and a concave mirror sequence arranged from a minified side to a magnified side. The outer diameter of the second lens is smaller than the outer diameter of the first lens. The outer diameter of the fifth lens is larger than the outer diameter of the fourth lens. The outer diameter of the sixth lens is smaller than the outer diameter of the fifth lens, wherein the first lens, the second lens, the aperture stop and the third lens are fixed relative to the concave mirror, and the fourth lens is capable of moving along a light axis relative to the concave mirror when the projection lens is in focusing process. The number of lenses with refractive power in the projection lens is 9 to 30. A projector using said projection lens is also provided.

Description

Projection lens and projector

The present invention relates to an optical lens and an optical device, and particularly relates to a projection lens and a projector for multiple imaging.

Compared with TV sets, projectors can project large-size images without using too much space, so projectors occupy a certain proportion in the market.

Generally speaking, if the projector wants to project to a larger screen size, it must have a longer projection distance. In contrast, if you want to project a large-size image at a shorter projection distance, a special wide-angle lens including a mirror is used to reduce the distance required for projection. However, in current designs, in order to effectively reduce lens distortion and chromatic aberration, more lens elements are often required to correct the aforementioned errors. However, the added lens has the problem of too large lens volume and high cost. Therefore, how to balance the volume, cost, and optical effect of the lens is one of the directions yet to be worked hard in this field.

One category of the present invention provides a projection lens and a projector, including a concave reflector, which allows the light emitted by the light valve to pass through the optical axis three times and produce three times of imaging, and has the requirements of large aperture, low distortion and low chromatic aberration. Better optical quality.

An embodiment of the present invention provides a projection lens, which includes a first lens, a second lens, an aperture stop, a third lens, a fourth lens, and a A fifth lens, a sixth lens, and a concave mirror. The first lens is the lens closest to the reduction side in the projection lens. The outer diameter of the second lens is smaller than the outer diameter of the first lens. The outer diameter of the fifth lens is larger than the outer diameter of the fourth lens. The sixth lens is the lens closest to the magnification side in the projection lens. The outer diameter of the sixth lens is smaller than the outer diameter of the fifth lens. When the projection lens is in focus, the positions of the first lens, the second lens, the aperture stop and the third lens relative to the concave mirror are fixed, and the fourth lens can be relative to the concave mirror Move along the optical axis. The number of lenses with refractive power in the projection lens is 9 to 30.

An embodiment of the present invention provides a projection lens, which includes a first lens group, a second lens group, and a concave mirror arranged in order from a reduction side to a magnification side. The first lens group includes a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side. The first lens is the lens closest to the reduction side in the first lens group. The first lens is an aspheric lens, and the outer diameter of the first lens is larger than the outer diameter of the second lens. The second lens group includes a fourth lens, a fifth lens and a sixth lens arranged in sequence from the reduction side to the magnification side. The fourth lens is the lens closest to the reduction side in the second lens group. The sixth lens is the lens closest to the magnification side in the second lens group. The outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens. When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move along the optical axis. The number of lenses with refractive power in the projection lens is 9 to 30.

An embodiment of the present invention provides a projection lens, which includes a first lens group, a second lens group, and a concave mirror arranged in order from a reduction side to a magnification side. The first lens group includes a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side. The first lens is the lens closest to the reduction side in the first lens group. The first lens is an aspheric lens, and the outer diameter of the first lens is larger than the outer diameter of the second lens. The second lens group includes a fourth lens, a fifth lens and a sixth lens arranged in sequence from the reduction side to the magnification side. The fourth lens is the lens closest to the reduction side in the second lens group. The sixth lens is the lens closest to the magnification side in the second lens group. The outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens. A reflection mirror is included between the fourth lens and the sixth lens of the second lens group. When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move along the optical axis relative to the concave mirror. The optical axis between the first lens group and the mirror in the projection lens has a turning point and is not a single straight line. The number of lenses with refractive power in the projection lens is 9 to 30.

An embodiment of the present invention provides a projector including a light source, a light valve, a projection lens, a first lens group, a second lens group, and a concave mirror. The light valve is arranged downstream of the light path of the light source. The projection lens is arranged downstream of the light path of the light valve, and includes a first lens group, a second lens group and a concave mirror arranged in sequence from a reduction side to an enlargement side. The first lens group includes a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side. The first lens is the lens closest to the reduction side in the first lens group. The outer diameter of the first lens is larger than the outer diameter of the second lens. The outer diameter of the first lens is twice or more than the diagonal length of the reaction surface of the light valve. The second lens group includes a fourth lens, a fifth lens and a sixth lens arranged in sequence from the reduction side to the magnification side. The fourth lens is the lens closest to the reduction side in the second lens group. The sixth lens is the lens closest to the magnification side in the second lens group. The outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens. When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move along the optical axis relative to the concave mirror. The number of lenses with refractive power in the projection lens is 9 to 30.

Based on the above, in an embodiment of the present invention, the projection lens and the projector using the projection lens can allow the light beam emitted by the light valve to pass through the optical axis three times to produce three times of imaging, and in a large aperture, low distortion and low chromatic aberration Good optical quality under requirements.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of a projector according to a first embodiment of the present invention. Please refer to Figure 1. In this embodiment, the projector 10 includes a light source 20, a light valve 30, and a projection lens 100.

The light source 20 is used to provide light of different wavelengths as a source of image light. In this embodiment, the light source 20 is, for example, a light-emitting diode (LED) or a laser diode that can provide visible light such as red, green, and blue or invisible light such as infrared light or ultraviolet light. laser diode, LD). However, the present invention does not limit the type or form of the light source 20, and the detailed structure and implementation of the light source 20 can obtain sufficient teachings, suggestions and implementation descriptions based on common knowledge in the technical field, and therefore will not be repeated.

The light valve 30 can be used to convert illumination light of different wavelengths into image light. The light valve 30 can be, for example, a reflective light modulator such as a liquid crystal on silicon panel (LCoS panel), a digital micro-mirror device (DMD), etc. The light valve 30 can also be light-transmitting. Transparent Liquid Crystal Panel (Transparent Liquid Crystal Panel), Electro-Optical Modulator (Electro-Optical Modulator), Magneto-Optic Modulator (Magneto-Optic Modulator), Acousto-Optic Modulator (AOM) and other penetrating light For the modulator, the present invention does not limit the type and type of the light valve 30. In this embodiment. The light valve 30 is a digital micro-mirror element, which includes a reflective surface composed of a plurality of micro-lenses, which can convert the illuminating light beam into a light beam with image information. The detailed steps and implementation manners of the foregoing conversion can obtain sufficient teachings, suggestions, and implementation descriptions based on common knowledge in the technical field, so they will not be repeated.

The projection lens 100 is used for projecting and imaging image light on a projection surface of a target. The projection lens 100 includes, for example, a combination of one or more lenses with refractive power. The lens includes, for example, a biconcave lens, a biconvex lens, a lens whose two optical surfaces are respectively concave-convex, plano-convex or plano-concave, and non-planar lenses. In some embodiments, in addition to elements such as lenses and apertures, elements such as flat mirrors or curved mirrors can be optionally added between each lens in the projection lens 100 to reflect and divert the light path of the beam, and The image light of the light valve 30 is projected to the projection target. The detailed design of the projection lens 100 will be described later.

In this embodiment, the projector 10 further includes components such as a glass cover 40, a frame 50, and a transmissive smooth image device 60.

The glass cover 40 is used to prevent dust and protect the light valve.

稜鏡50, used to adjust the light path of light of different wavelengths. In this example, the design of the total reflection surface can be used to reflect the beam of a specific incident angle range and allow the beam of another incident angle range to pass through. In this example, the scallop 50 is composed of two single scallops in the shape of a triangular cylinder, but it is not limited, and it may only include a single single scallop or include 3 or more single scallops. ; In this example, the quintile 50 is a TIR ridge according to the travel mode of the light path; but it can also be replaced by an RTIR ridge.

The Transmissive Smooth Picture (TSP) 60 can shake along a single axis or multiple axes so that the pixel points of the projected image are blurred to a small extent, thereby increasing the resolution.

In this example, the light valve 30 is arranged downstream of the optical path of the light source 20, and the projection lens 100 is arranged downstream of the optical path of the light valve 30. In detail, in this embodiment, the light beam provided by the light source 20 passes through the beam 50, the glass cover 40 and the light valve 30 in order. The light valve 30 converts the light beam into an image light beam with image information. The image light beam can then sequentially pass through the glass cover 40, the ridge 50, the penetrating smooth image device 60 to the projection lens 100, and finally the image light beam passes through the projection lens 100. It is projected and imaged on a projection surface outside the projector 10.

2 is a schematic cross-sectional view of the projection lens of the first embodiment of the invention. Please refer to Figure 2. The projection lens 100 shown in FIG. 2 can at least be applied to the projector 10 shown in FIG. 1, so the following will take the projector 10 shown in FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100 includes a lens group 150, a lens group 140, and a concave mirror 130.

In this example, the concave mirror 130 has an aspherical surface. The opening of the concave mirror 130 may optionally be provided with a light-transmitting glass cover (not shown in FIG. 1) to seal the concave portion of the concave mirror 130 into a sealed office for dust-proof effect. In this example, the concave mirror 130 is axisymmetric with respect to the optical axis A of the projection lens 100, but it is not limited to this. When necessary, the concave mirror 130 can be cut as required. For example, the concave mirror 130 can be cut at a specific part above the optical axis and close to the light emitting direction, as an example. Furthermore, when the concave mirror 130 is cut, the concave mirror 130 will have an upper opening and a side opening facing the lens group 140. At this time, a glass cover can be selectively provided on the upper opening and the side opening to prevent dust. effect.

In this embodiment, the number of lenses with refractive power in the projection lens 100 is 13 pieces. The number of lenses with diopter in the projection lens 100 is more than 9, and when there are 15 and 30 or less, it has the best and better cost-effectiveness. In addition, in this embodiment, the projection lens 100 is a fixed focus lens.

In this embodiment, the lens group 150 and the lens group 140 are co-optical axis. In addition, the number of lenses with refractive power in the lens group 140 is 7, and when the number of lenses included in the lens group 140 is less than or equal to 7, 10, or 15, it has the best, better, and better cost-effectiveness. In addition, in this embodiment, the lens group 140 includes at least two aspheric lenses, which can effectively reduce the number of lenses and improve aberrations.

In this embodiment, the lens group 150 includes six lenses and an aperture stop 160 provided therein. When the number of lenses included in the lens group 150 is less than or equal to 6, 10, or 15, it has the best and better results. Best and best cost-effectiveness.

In detail, in this embodiment, the lens group 150, the lens group 140, and the concave mirror 130 of the projection lens 100 are arranged in order from the reduction side 110 to the magnification side 120 along the optical axis A of the projection lens 100. The reduction side 110 is the light input side of the projection lens 100, and the magnification side 120 is the light output side of the projection lens 100. In the side of the projection lens 100 facing the reduction side 110, the light valve 30, the glass cover 40, the beam 50 and the transmissive smooth image device 60 are arranged in order from the reduction side 110 to the magnification side 120 before the projection lens 100.

In this embodiment, in the lens group 150, along the optical axis A of the projection lens 100, from the reduction side 110 to the magnification side 120 are arranged in sequence, including lens L13, lens L12, lens L11, lens L10, lens L9, and aperture stop. 160 and lens L8. In the lens group 140, a lens L7, a lens L6, a lens L5, a lens L4, a lens L3, a lens L2, and a lens L1 are arranged in order from the reduction side 110 to the magnification side 120 along the optical axis A. In other words, the lens L13 is the lens closest to the reduction side 110 in the lens group 150 and is also the lens closest to the reduction side 110 in the projection lens 100. The lens L8 is the lens closest to the magnification side 120 in the lens group 150. The lens L7 is the lens closest to the reduction side 110 in the lens group 140. The lens L1 is the lens closest to the magnification side 120 in the lens group 140, and is also the lens closest to the magnification side 120 in the projection lens 100 and has a refractive power. In this embodiment, the aperture stop 160 is provided between the lens L8 and the lens L9, that is, it is not located at the first or last optical element of the lens group 150.

In this embodiment, the lens L1 and the lens L2 are compound lenses, and the compound lenses can be fixed to each other in a variety of ways, for example, clamping by a mechanism or fixing the two with glue. The lens L9, the lens L10, and the lens L11 are compound lenses, for example, a triplet lens. In this example, the aforementioned compound lenses are all cemented lenses. In this embodiment, the lens L4, the lens L6, and the lens L13 are aspheric lenses, that is, the number of aspheric lenses is three.

In addition, in this embodiment, the lens L7 is the lens closest to the reduction side 110 in the lens group 140.

In this embodiment, there are two size parameters in the lens, one is the clear aperture RF (Clear aperture, CA), also known as the optical effective diameter. The clear aperture can be simply understood as the optical effective area of each lens. The other is the outer diameter TRF of the lens. The outer diameter TRF refers to the maximum diameter of the outer contour of the lens including the clear aperture and other non-optical effective areas. In this example, the clear aperture RF and the outer diameter TRF are positively correlated, but there is no specific proportional relationship between the clear aperture RF and the outer diameter TRF of the lens. The clear aperture RF and outer diameter TRF of lens L7, lens L6, and lens L5 all gradually increase in sequence; while the clear aperture RF and outer diameter TRF of lens L5, lens L4, lens L3, lens L2, and lens L1 all follow The order is gradually decreasing; and the clear aperture RF and outer diameter TRF of lens L13, lens L12, lens L11, lens L10, and lens L9 are gradually decreasing, while the clear aperture RF of lens L8 is larger than that of lens L13, lens L12, and lens L11, respectively. , The clear aperture of lens L10 and lens L9. The outer diameter TRF of the lens L8 is also larger than the outer diameters TRF of the lens L13, the lens L12, the lens L11, the lens L10, and the lens L9, respectively.

The lens L1 is a lens in the lens group 140 that is closest to the magnification side 120 and has the smallest clear aperture RF and the smallest outer diameter TRF. Specifically, in the lens group 140, the change of the clear aperture RF and the outer diameter TRF of the lens changes from the reduction side 110 to the magnification side 120 first from small to large and then from large to small.

In this embodiment, the projection lens 100 is an ultra-short focal lens. For example, the total lens length TL is from the surface of the lens L13 facing the reduction side 110 (that is, the surface S25) to the concave mirror 130 (that is, the surface S1) on the projection lens 100. The distance on the optical axis A, and EFL is the effective focal length of the projection lens 100. When TL/EFL≧100, TL/EFL≧70, and TL/EFL≧50, the required projection distance performance is the best, better, and best. In this example, TL/EFL is 106.1. On the other hand, in this embodiment, when the projection lens 100 is in focus, each lens and aperture in the lens group 150 are fixed on the optical axis A of the projection lens 100, and whether it is horizontal or perpendicular to the optical axis A The position and distance relative to the concave mirror 130 in both directions are fixed. When focusing, one or more lenses in the lens group 140 are movable relative to the concave mirror 130. In this example, the lens closest to the lens group 150, such as the lens L7, can move relative to the concave mirror 130 along the optical axis A of the projection lens. Since all the lenses in the lens group 150 are fixed during focusing, the lens of the lens group 150 closest to the reduction side needs to be movable during focusing, so that the lens group 140 and the lens group 150 can be distinguished. In this example, the concave mirror 130, the lens group 140, and the lens group 150 have a common optical axis.

Fig. 3 is a schematic diagram of the light valve according to the first embodiment of the present invention. Please refer to Figure 2 and Figure 3. In addition, the reduction side 110 of the projection lens 100 has substantially telecentric characteristics. For example, a telecentric lens is a lens with at least one infinity pupil. As far as the chief ray is concerned, having an infinite pupil means (a) if the entrance pupil is at infinity, the chief ray is parallel to the optical axis of the object space, or (b) if the exit pupil is at infinity, the chief ray and The optical axis of the image space is parallel. In practical applications, the telecentric pupil does not necessarily have to be infinitely far away, because a lens with an entrance or exit pupil at a sufficiently large distance from the optical surface of the lens can essentially operate as a telecentric system. The chief ray of this type of lens is essentially parallel to the optical axis, so the lens is generally functionally equivalent to a lens with the theoretical (Gaussian) position of the pupil at infinity. In this example, when the light beam enters the projection lens from the reduction side 110, each chief ray L (chief ray) of the light beam is substantially parallel to the optical axis A of the projection lens 100, respectively. Each chief ray L travels substantially parallel to the optical axis of the projection lens 100. For example, the inclination angle of the chief ray L with respect to the optical axis is less than or equal to 5 degrees, and the present invention is not limited to this.

Again, please refer to Figure 3. The projection lens 100 has a corresponding image height IMH on the image plane. In this example, a light valve 30 is provided on the image plane on the reduced side, and the image height IMH is equal to the maximum straight line length from the optical axis A to the diagonal of the light valve 30.

Corresponding to the telecentric characteristics of the reduced side of the projection lens 100, in this example, the outer diameter TRF (including the optical effective area and ineffective area) and the clear aperture RF of the lens closest to the reduced side 110 in the projection lens 100 are larger than the image height IMH Twice or more. In this example, the clear aperture RF divided by the image height IMH (RF/IMH) is approximately 3. The outer diameter TRF is larger than the clear aperture RF, so the outer diameter TRF divided by the image height IMH (TRF/IMH) is also greater than 3.

In this example, the projection lens 100 is a tertiary imaging system. The first intermediate image of the projection lens 100 is formed between the lens L5 and the lens L4. The second intermediate image is formed between the lens L1 and the concave mirror 130. Subsequently, the projection lens 100 projects the light beam onto a projection surface (for example, a projection screen) to form an image, which is a three-time image.

In this example, the light exit end of the lens L5 (facing the lens L4 side) and the light entrance end of the lens L4 (facing the lens L5 side) both have non-telecentric characteristics. In addition, each chief ray L of the light beam between the lens L5 and the lens L4 is not substantially parallel to the optical axis A of the projection lens 100.

In this example, the projection lens 100 can project the light input from the light valve 30 located on the first image plane onto the second image plane of the projection surface for imaging. In this example, a projection screen or a flat surface can be provided on the projection surface to improve the image quality. The light beam starting from the center of the aforementioned first image surface and reaching the center of the second image surface will pass through the optical axis of the lens group 140, the lens group 150 or the concave mirror 130 three times in total.

For example, the projection lens 100 makes the chief ray L of the light beam passed into the projection lens 100 by the light valve 30 between the optical path of the lens L9 and the lens L10, between the optical path of the lens L1 and the concave mirror 130, and downstream of the optical path of the concave mirror 130 Pass through the optical axis A of the projection lens 100 three times in total.

In this example, the throw ratio of the projection lens 100 is about 0.22, and the aperture value F/# is 1.8, which can be adjusted to be between 1.7 and 1.9.

In this embodiment, the actual design of the aforementioned components can be seen in Table 1 below.

Table I TL(mm)=233.5; EFL (mm) =2.2; TL/EFL=106.1; RF (mm)=26.9; IMH (mm)=8.945; RF/IMH=3.0; F/#=1.8; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1* -20.02 56.39 72.4 Lens L1 S2 -19.74 10.45 1.50 81.5 11.4 Lens L2 S3 9.49 1.00 1.67 32.1 14.0 S4 44.49 0.20 16.2 Lens L3 S5 -162.60 4.84 1.67 47.2 17.5 S6 20.74 11.84 19.1 Lens L4 S7* 63.11 8.00 1.53 56.3 31.4 S8* 130.25 20.74 35.0 Lens L5 S9 -112.15 12.67 1.66 50.9 49.7 S10 51.39 6.00 50.7 Lens L6 S11* -18.83 12.60 1.53 56.3 44.0 S12* -9.43 22.59 32.0 Lens L7 S13 -101.81 12.60 1.49 70.2 32.3 S14 45.43 2.01 31.9 Lens L8 S15 -99.00 4.83 1.74 44.8 29.0 S16 64.24 12.90 28.2 Aperture diaphragm 160 S17 Unlimited 0.62 10.2 Lens L9 S18 32.23 7.90 1.65 33.8 10.3 Lens L10 S19 -15.47 10.69 1.50 81.5 15.3 Lens L11 S20 11.72 1.00 1.67 32.1 18.3 S21 45.51 0.20 21.8 Lens L12 S22 Unlimited 4.81 1.80 22.8 23.5 S23 30.73 0.20 24.8 Lens L13 S24* -46.80 8.42 1.51 64.0 26.3 S25* 20.20 0.10 26.9 Transmissive smooth imaging device 60 S26 Unlimited 2 1.52 S27 Unlimited 3.2 稜鏡50 S28 Unlimited 16 1.73 S29 Unlimited 0.8 Glass cover 40 S30 Unlimited 1.1 1.51 S31 Unlimited 0.303

Please refer to Figure 2 and Table 1 at the same time. Specifically, in the projection lens 100 of this embodiment, the concave mirror 130 has a surface S1, and the surface S1 is an aspheric surface. The lens L1 has a surface S2 from the magnification side 120 to the reduction side 110, and the lens L2 has a surface S3 and a surface S4 in sequence from the magnification side 120 to the reduction side 110, and so on. The surface corresponding to each element will not be repeated. Among them, the imaging surface of the aperture diaphragm 160 is represented by the surface S17, and its radius of curvature is infinite (that is, the plane perpendicular to the optical axis A); and the lens L1 and the lens L2, the lens L9 and the lens L10, and the lens L11 and the lens L12 has a common surface S3, a surface S19, and a surface S20, respectively, which means that the lens L2 and the lens L3 are two lenses connected along the optical axis A, or a doublet lens. The lens L9, the lens L10, and the lens L11 are three lenses connected along the optical axis A, or a triplet lens.

In addition, the interval in Table 1 is the reciprocal of the interval between the next surface of the surface from the magnification side 120 to the reduction side 110. For example, the thickness of the lens L1 is 10.45 mm, the thickness of the lens L2 is 1.00 mm, and the lens The distance between L2 and lens L3 is 0.20 mm, and so on without repeating it. In Table 1, the one marked with * next to the “surface” number indicates that it is an aspheric surface.

In addition, the radius of curvature in Table 1 is the radius of curvature of the surface, and its positive and negative values represent the direction of curvature. For example, the radius of curvature of the surface S5 of the lens L3 is negative, and the radius of curvature of the surface S6 of the lens L3 is positive. , Therefore, the lens L3 is a biconvex lens. The radius of curvature of the surface S11 of the lens L6 is negative, and the radius of curvature of the surface S12 of the lens L6 is negative. Therefore, the lens L6 is a meniscus lens with a concave surface facing the reduction side 110, and so on.

In this embodiment, the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, and the surface S24 and the surface S25 of the lens L13 are aspherical surfaces. Table 2 below lists the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, and the surface S24 and the surface S25 of the lens L13. . The aspheric polynomial can be expressed by the following formula: (1)

Where x is the offset in the direction of the optical axis A (sag), c'is the reciprocal of the radius of the Osculating Sphere, that is, the reciprocal of the radius of curvature close to the optical axis, K is the quadric coefficient, y It is the height of the aspheric surface, which is the height from the center of the lens to the edge of the lens. A-G respectively represent the aspheric coefficients of the aspheric polynomials.

Table II S1 S7 S8 S11 K -1.10 0 0 -1.85 A 6.48E-06 5.91E-05 8.42E-05 -1.46E-05 B -1.40E-08 -4.18E-07 -1.13E-07 -6.97E-08 C 1.69E-11 1.17E-09 5.50E-11 2.28E-10 D -1.60E-14 -1.21E-12 1.71E-13 -3.80E-13 E 9.46E-18 0 0 4.48E-16 F -3.11E-21 0 0 -2.29E-19 G 3.82E-25 0 0 0 S12 S24 S25 K -1.76 0 0 A -1.39E-04 2.04E-05 -3.61E-05 B 1.66E-07 3.77E-08 1.13E-07 C 4.62E-10 -1.10E-10 -3.92E-10 D -9.58E-13 0 0 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 4 is an imaging optical simulation data diagram of the projection lens according to the first embodiment of the present invention. Please refer to Figure 4. 4 is a graph of the optical transfer function (modulation transfer function, MTF) of the projection lens 100, the horizontal axis of which is the spatial frequency in cycles per millimeter (mm), and the vertical axis of the optical transfer function Modulus of the optical transfer function, T represents the curve in the meridian direction, S represents the curve in the sagittal direction, and the value after "TS" represents the image height. It can be verified that the optical transfer function curve displayed by the projection lens 100 of this embodiment is within the standard range, and therefore has a good optical imaging quality, as shown in FIG. 4.

FIG. 5 is a schematic cross-sectional view of a projection lens according to a second embodiment of the present invention. Please refer to Figure 5. The projection lens 100A shown in FIG. 5 can at least be applied to the projector 10 shown in FIG. 1, so the following will take the projector 10 of FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100A of this embodiment is similar to the projection lens 100 shown in FIG. 2. The main difference between the two is that in this embodiment, the lens group 150 of the projection lens 100A has two groups of doublet lenses, and the lens group 140 also has Two sets of double cemented lenses.

In detail, in the present embodiment, in the lens group 150, the lens group 150 includes lens L15, lens L14, lens L13, lens L12, lens L11, lens L10, Aperture stop 160 and lens L9. In the lens group 140, a lens L8, a lens L7, a lens L6, a lens L5, a lens L4, a lens L3, a lens L2, and a lens L1 are arranged in order from the reduction side 110 to the magnification side 120 along the optical axis A. In other words, the lens L15 is the lens closest to the reduction side 110 in the lens group 150, and is also the lens closest to the reduction side 110 in the projection lens 100A. The lens L9 is the lens closest to the magnification side 120 in the lens group 150. The lens L8 is the lens closest to the reduction side 110 in the lens group 140. The lens L1 is the lens closest to the magnification side 120 in the lens group 140 and is also the lens closest to the magnification side 120 in the projection lens 100A.

In this embodiment, the actual design of the aforementioned components can be seen in Table 3 below. The interpretation of Table 3 is the same as that of Table 1, so I won’t repeat it.

Table Three TL(mm)=233.5; EFL (mm) =2.2; TL/EFL=106.1; RF (mm)=25.5; IMH (mm)=8.945; RF/IMH=2.9; F/#=1.7; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1* -20.43 54.55 72.2 Lens L1 S2 -17.24 11.73 1.50 81.5 13.1 Lens L2 S3 8.85 1.00 1.61 37.0 12.4 S4 26.78 0.20 14.2 Lens L3 S5 -142.03 7.50 1.83 42.7 15.9 Lens L4 S6 11.85 11.31 1.72 29.5 18.0 S7 53.85 3.09 29.2 Lens L5 S8* 23.52 8.00 1.53 56.3 30.5 S9* 25.86 21.61 33.9 Lens L6 S10 -135.55 11.55 1.76 40.1 49.1 S11 54.27 1.23 50.1 Lens L7 S12* -19.69 12.60 1.53 56.3 44.6 S13* -9.14 23.90 32.2 Lens L8 S14 -259.90 12.57 1.66 50.9 32.5 S15 59.82 1.84 32.3 Lens L9 S16 -175.40 5.08 1.76 56.3 30.5 S17 51.32 12.95 29.9 Aperture diaphragm 160 S18 Unlimited 0.88 10.9 Lens L10 S19 34.02 1.00 1.70 30.1 11.2 Lens L11 S20 -10.43 3.57 1.70 41.2 12.5 S21 -31.95 1.11 13.4 Lens L12 S22 -23.20 10.88 1.50 81.5 15.4 Lens L13 S23 13.50 1.00 1.67 32.1 17.9 S24 -149.35 1.24 20.5 Lens L14 S25 -51.22 5.51 1.80 22.8 23.7 S26 40.30 0.20 24.6 Lens L15 S27* -34.19 7.40 1.51 64.0 25.2 S28* 23.27 25.5 Transmissive smooth imaging device 60 S29 Unlimited 2.0 1.52 58.6 S30 Unlimited 3.2 稜鏡50 S31 Unlimited 16.0 1.73 28.3 S32 Unlimited 0.8 Glass cover 40 S33 Unlimited 1.1 1.51 62.9 S34 Unlimited 0.3

Please refer to Figure 5 and Table 3 at the same time. Among them, the lens L1 and the lens L2, the lens L3 and the lens L4, the lens L10 and the lens L11, and the lens L12 and the lens L13 are compound lenses, such as double cemented lenses. Lens L5, lens L7, and lens L15 are aspheric lenses. In other words, the surface S1 of the concave mirror 130, the surface S8 and the surface S9 of the lens L5, the surface S12 and the surface S13 of the lens L7, and the surface S27 and the surface S28 of the lens L15 are aspherical surfaces. In addition, the rest of the optical characteristics and effects can be described with reference to the projection lens 100 in FIG. 1, and will not be repeated here.

Table 4 below lists the surface S1 of the concave mirror 130, the surface S8 and the surface S9 of the lens L5, the surface S12 and the surface S13 of the lens L7, the surface S27 and the surface S28 of the lens L15, the quadric coefficient values K and the aspheric coefficients AG of each order. .

Table Four S1 S8 S9 S12 K -1.12 0 0 -2.50 A 5.70E-06 -2.30E-05 1.94E-05 -3.03E-05 B -1.35E-08 -4.37E-08 4.71E-08 -2.86E-08 C 1.65E-11 7.77E-11 -6.99E-11 1.62E-10 D -1.57E-14 -9.50E-14 -4.09E-16 -3.37E-13 E 9.46E-18 0 0 4.48E-16 F -3.26E-21 0 0 -2.29E-19 G 4.50E-25 0 0 0 S13 S27 S28 K -1.69 0 0 A -1.60E-04 2.83E-05 -4.29E-05 B 2.99E-07 -1.06E-10 7.96E-08 C 8.67E-11 3.89E-10 7.41E-11 D -5.34E-13 -6.24E-13 -5.81E-13 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 6 is an imaging optical simulation data diagram of the projection lens according to the second embodiment of the present invention. Please refer to Figure 6. FIG. 6 is an optical transfer function (modulation transfer function, MTF) diagram of the projection lens 100A. The interpretation method of FIG. 6 is the same as that of FIG. 3, so it will not be repeated. It can be verified that the optical transfer function curve displayed by the projection lens 100A of this embodiment is within the standard range, so it has good optical imaging quality.

FIG. 7 is a schematic cross-sectional view of a projection lens according to a third embodiment of the present invention. Please refer to Figure 7. The projection lens 100B shown in FIG. 7 can be applied to at least the projector 10 shown in FIG. 1, so the following will take the projector 10 of FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100B of this embodiment is similar to the projection lens 100 shown in FIG. 2. The main difference between the two is that, in this embodiment, the lens group 150 of the projection lens 100B has two sets of double cemented lenses, and the lens group 140 also has Two sets of double cemented lenses. In addition, the position of the aspheric lens in the lens group 140 of the projection lens 100B is different from the position of the aspheric lens in the lens group 140 of the projection lens 100.

In this embodiment, the actual design of the aforementioned components can be seen in Table 5 below. The interpretation of the following table is the same as that of Table 1, and the repetitive content will not be repeated.

Table 5 TL(mm)=233.5; EFL (mm)=2.2; TL/EFL=106.1; RF (mm)=25.7; IMH (mm)=8.945; RF/IMH=2.9; F/#=1.7; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1* -21.37 58.27 77.07 Lens L1 S2 -16.87 9.30 1.50 81.5 11.6 Lens L2 S3 10.64 5.18 1.82 25.5 11.2 S4 26.96 0.20 15.7 Lens L3 S5 -51.81 12.60 1.85 40.0 21.0 Lens L4 S6 15.68 2.00 1.59 38.3 24.6 S7 -58.15 10.16 28.6 Lens L5 S8 40.53 10.03 1.75 40.5 33.1 S9 22.66 16.21 37.2 Lens L6 S10* -106.89 11.49 1.53 56.3 46.0 S11* 37.52 0.23 47.2 Lens L7 S12* -35.09 12.43 1.53 56.3 42.4 S13* -9.80 19.83 30.8 Lens L8 S14 -45.12 5.22 1.84 40.2 33.2 S15 -604.37 12.45 33.0 Lens L9 S16 -239.94 5.09 1.85 33.8 28.5 S17 45.48 11.57 28.0 Aperture diaphragm 160 S18 Unlimited 3.58 10.9 Lens L10 S19 21.67 1.00 1.70 28.8 12.1 Lens L11 S20 -11.80 4.49 1.71 46.8 14.5 S21 -88.68 0.76 15.8 Lens L12 S22 -71.63 6.83 1.50 81.5 17.0 Lens L13 S23 12.19 1.00 18.4 S24 34.76 0.20 21.4 Lens L14 S25 -77.11 5.17 1.80 22.8 24.5 S26 37.19 1.10 25.2 Lens L15 S27* -59.88 7.10 1.51 64.0 25.0 S28* 20.40 3.10 25.7 Transmissive smooth imaging device 60 S29 Unlimited 2.0 1.52 58.6 S30 Unlimited 3.2 稜鏡50 S31 Unlimited 16.0 1.73 28.3 S32 Unlimited 0.8 Glass cover 40 S33 Unlimited 1.1 1.51 62.9 S34 Unlimited 0.3

Please refer to Figure 7 and Table 5 at the same time. Among them, the lens L1 and the lens L2, the lens L3 and the lens L4, the lens L10 and the lens L11, and the lens L12 and the lens L13 are compound lenses, such as double cemented lenses. Lens L6, lens L7, and lens L15 are aspheric lenses. In other words, the surface S1 of the concave mirror 130, the surface S10 and the surface S11 of the lens L6, the surface S12 and the surface S13 of the lens L7, and the surface S27 and the surface S28 of the lens L15 are aspherical surfaces. In addition, the rest of the optical characteristics and effects can be described with reference to the projection lens 100 in FIG. 1, and will not be repeated here.

Table 6 below lists the surface S1 of the concave mirror 130, the surface S10 and the surface S11 of the lens L6, the surface S12 and the surface S13 of the lens L7, the surface S27 and the surface S28 of the lens L15, the quadric coefficient values K and the aspheric coefficients A-G of each order.

Table 6 S1 S10 S11 S12 K -1.09 0 0 -0.35 A 5.61E-06 9.35E-06 -7.02E-06 -4.50E-05 B -1.29E-08 1.03E-08 2.28E-08 1.91E-08 C 1.64E-11 -4.85E-11 -2.98E-11 1.25E-10 D -1.57E-14 3.11E-14 5.32E-15 -3.19E-13 E 9.46E-18 0 0 4.48E-16 F -3.27E-21 0 0 -2.29E-19 G 4.80E-25 0 0 0 S13 S27 S28 K -1.76 0 0 A -1.76E-04 3.87E-05 -2.95E-05 B 4.11E-07 -1.02E-08 2.40E-08 C 5.81E-12 2.98E-10 1.81E-10 D -7.53E-13 3.13E-13 3.64E-14 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 8 is an imaging optical simulation data diagram of the projection lens according to the third embodiment of the present invention. Please refer to Figure 8. FIG. 8 is an optical transfer function (modulation transfer function, MTF) graph of the projection lens 100B. The interpretation method of FIG. 8 is the same as that of FIG. 3 and will not be repeated. It can be verified that the optical transfer function curve displayed by the projection lens 100B of this embodiment is within the standard range, so it has good optical imaging quality.

FIG. 9 is a schematic cross-sectional view of a projection lens according to a fourth embodiment of the present invention. Please refer to Figure 9. The projection lens 100C shown in FIG. 9 can at least be applied to the projector 10 shown in FIG. 1, so the following will take the projector 10 shown in FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100C of this embodiment is similar to the projection lens 100 shown in FIG. 2. The main difference between the two is that in this embodiment, the lens closest to the reduction side 110 in the lens group 140 of the projection lens 100B is an aspheric lens.

In this embodiment, the actual design of the aforementioned components can be seen in Table 7 below. The interpretation of the following table is the same as that of Table 1, and the repetitive content will not be repeated.

Table Seven TL(mm)=233.5; EFL (mm)=2.2; TL/EFL=106.1; RF (mm)=25.5; IMH (mm)=8.945; RF/IMH=2.9; F/#=1.9; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1* -18.53 50.63 63.3 Lens L1 S2 -17.13 12.60 1.50 81.5 13.8 Lens L2 S3 9.73 1.00 1.63 35.70 14.1 S4 32.12 0.20 16.1 Lens L3 S5 -51.92 12.39 1.50 81.5 19.2 S6 30.92 6.23 26.3 Lens L4 S7* 1705.03 8.00 1.53 56.3 34.0 S8* -692.05 28.51 36.5 Lens L5 S9 -82.83 14.61 1.64 55.40 54.1 S10 58.05 15.72 54.8 Lens L6 S11* -26.86 12.38 1.53 56.3 43.4 S12* -10.52 15.20 31.0 Lens L7 S13 -55.31 8.48 1.64 55.40 31.5 S14 35.34 16.73 31.2 Aperture diaphragm 160 S15 Unlimited 5.81 10.2 Lens L8 S16 70.73 1.00 1.60 38.00 13.5 Lens L9 S17 -13.18 8.16 1.50 81.5 15.0 Lens L10 S18 11.54 1.00 1.70 30.10 16.3 S19 88.24 0.20 19.7 Lens L11 S20 -544.05 4.77 1.80 22.8 20.8 S21 26.96 1.36 22.3 Lens L12 S22* -42.36 8.52 1.51 64.0 24.6 S23* 19.17 25.5 Transmissive smooth imaging device 60 S24 Unlimited 2 1.52 58.6 S25 Unlimited 3.2 稜鏡50 S26 Unlimited 16 1.73 28.3 S27 Unlimited 0.8 Glass cover 40 S28 Unlimited 1.1 1.51 62.9 S29 Unlimited 0.303

Please refer to Figure 9 and Table 7 at the same time. Among them, lens L1 and lens L2 are compound lenses, such as double cemented lenses, and lens L8, lens L9, and lens L10 are compound lenses, such as triple cemented lenses. Lens L4, lens L6, and lens L12 are aspheric lenses. In other words, the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, and the surface S22 and the surface S23 of the lens L12 are aspherical surfaces. In addition, the rest of the optical characteristics and effects can be described with reference to the projection lens 100 in FIG. 1, and will not be repeated here.

Table 8 below lists the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, the surface S22 and the surface S23 of the lens L12, the quadric coefficient values K and the aspheric coefficients A-G of each order.

Table 8 S1 S7 S8 S11 K -1.12 0 0 -5.38 A 6.22E-06 5.17E-05 8.26E-05 -2.56E-05 B -1.50E-08 -2.44E-07 -1.34E-07 -2.09E-08 C 1.67E-11 4.99E-10 1.51E-10 1.55E-10 D -1.60E-14 -4.19E-13 -1.61E-13 -3.40E-13 E 9.46E-18 0 0 4.48E-16 F -2.94E-21 0 0 -2.29E-19 G 9.40E-26 0 0 0 S12 S22 S23 K -1.77 0 0 A -1.14E-04 1.92E-05 -4.38E-05 B -1.62E-08 3.36E-08 1.35E-07 C 1.12E-09 -7.73E-11 -4.70E-10 D -1.78E-12 6.43E-13 1.08E-12 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 10 is an imaging optical simulation data diagram of the projection lens according to the fourth embodiment of the present invention. Please refer to Figure 10. FIG. 10 is an optical transfer function (modulation transfer function, MTF) diagram of the projection lens 100C. The interpretation method of FIG. 10 is the same as that of FIG. 3 and will not be repeated. It can be verified that the optical transfer function curve displayed by the projection lens 100C of this embodiment is within the standard range, and therefore has a good optical imaging quality, as shown in FIG. 10.

FIG. 11 is a schematic cross-sectional view of a projection lens according to a fifth embodiment of the present invention. Please refer to Figure 11. The projection lens 100D shown in FIG. 11 can be applied to at least the projector 10 shown in FIG. 1, so the following will take the projector 10 shown in FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100D of this embodiment is similar to the projection lens 100 shown in FIG. 2. The main difference between the two is that in this embodiment, the lens group 150 of the projection lens 100D has two sets of double cemented lenses.

In this embodiment, the actual design of the aforementioned components can be seen in Table 9 below. The interpretation of the following table is the same as that of Table 1, and the repetitive content will not be repeated.

Table 9 TL(mm)=233.5; EFL (mm)=2.2; TL/EFL=106.1; RF (mm)=26.3; IMH (mm)=8.945; RF/IMH=2.9; F/#=1.8; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1* -19.75 58.06 72.4 Lens L1 S2 -19.50 11.17 1.50 81.5 10.7 Lens L2 S3 8.96 1.44 1.63 35.7 13.6 S4 39.59 0.20 16.2 Lens L3 S5 -81.49 6.14 1.49 70.2 18.7 S6 18.24 10.25 20.9 Lens L4 S7* 44.27 8.00 1.53 56.3 30.1 S8* 62.23 20.78 33.9 Lens L5 S9 -95.40 11.66 1.64 55.40 46.0 S10 50.92 0.20 46.8 Lens L6 S11* -17.39 12.60 1.53 56.3 41.5 S12* -9.12 25.64 29.6 Lens L7 S13 185.94 12.60 1.83 37.2 29.3 S14 49.90 2.13 30.2 Lens L8 S15 -85.6334 5.51 1.50 81.5 27.9 S16 43.25 12.34 27.0 Aperture diaphragm 160 S17 Unlimited 5.30 11.5 Lens L9 S18 15.85 1.88 1.65 33.8 13.5 Lens L10 S19 -43.54 5.78 1.50 81.5 16.3 S20 15.96 0.20 18.1 Lens L11 S21 272.56 5.68 1.50 81.5 19.7 Lens L12 S22* 16.30 1.10 1.76 27.5 20.6 S23* 95.53 1.68 23.0 Lens L13 S24 -94.71 5.83 1.80 22.8 25.9 S25 33.80 0.20 26.7 Lens L14 S26* -53.65 7.13 1.51 64.0 26.3 S27* 45.97 25.9 Transmissive smooth imaging device 60 S28 Unlimited 2 1.52 58.6 S29 Unlimited 3.2 稜鏡50 S30 Unlimited 16 1.73 28.3 S31 Unlimited 0.8 Glass cover 40 S32 Unlimited 1.1 1.51 62.9 S33 Unlimited 0.303

Please refer to Figure 11 and Table 9 at the same time. Among them, the lens L1 and the lens L2, the lens L9 and the lens L10, and the lens L11 and the lens L12 are compound lenses, such as double cemented lenses. Lens L4, lens L6, and lens L14 are aspheric lenses. In other words, the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, and the surface S26 and the surface S27 of the lens L14 are aspherical surfaces. In addition, the rest of the optical characteristics and effects can be described with reference to the projection lens 100 in FIG. 1, and will not be repeated here.

The following table ten lists the surface S1 of the concave mirror 130, the surface S7 and the surface S8 of the lens L4, the surface S11 and the surface S12 of the lens L6, the surface S26 and the surface S27 of the lens L14, the quadric coefficient values K and the aspheric coefficients A-G of each order.

Table 10 S1 S7 S8 S11 K -1.19 0 0 -1.52 A 5.66E-06 4.70E-05 7.00E-05 -1.53E-05 B -1.43E-08 -3.61E-07 -5.10E-08 -8.25E-08 C 1.74E-11 1.10E-09 -1.71E-10 2.22E-10 D -1.62E-14 -1.09E-12 5.83E-13 -3.39E-13 E 9.46E-18 0 0 4.48E-16 F -3.14E-21 0 0 -2.29E-19 G 4.09E-25 0 0 0 S12 S26 S27 K -1.58 0 0 A -1.38E-04 2.01E-05 -1.10E-05 B -8.37E-09 4.43E-08 7.93E-08 C 1.21E-09 -1.00E-10 -3.34E-10 D -1.80E-12 -3.37E-14 3.32E-13 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 12 is an imaging optical simulation data diagram of the projection lens according to the fifth embodiment of the present invention. Please refer to Figure 12. FIG. 12 is a graph of the optical transfer function (MTF) of the projection lens 100D. The interpretation method of FIG. 12 is the same as that of FIG. 3, and the repeated parts will not be repeated. It can be verified that the optical transfer function curve displayed by the projection lens 100D of this embodiment is within the standard range, and therefore has a good optical imaging quality, as shown in FIG. 12.

FIG. 13A is a schematic cross-sectional view of a projection lens according to a sixth embodiment of the invention. FIG. 13B is a schematic cross-sectional view of a projection lens according to a seventh embodiment of the invention. Please refer to Figure 13A and Figure 13B. The projection lens 100E shown in FIG. 13A can be used at least in the projector 10 shown in FIG. 1, so the following will take the projector 10 shown in FIG. 1 as an example for description, but the present invention is not limited to this. The projection lens 100E of this embodiment is similar to the projection lens 100 shown in FIG. 2. The main difference between the two is that in this embodiment, the lens group 150 of the projection lens 100E has two sets of double cemented lenses. In addition, the projection lens 100E further includes a glass cover 170, and the glass cover 170 is located between the lens group 140 and the concave mirror 130. In the example of FIG. 13A, there is a reserved space between the glass cover 170 and the concave mirror 130, but its size and position are only for illustration. In fact, the glass cover 170 can be translated as required and connected with the concave mirror 130 and its size is large enough to close the concave mirror. The entire opening of 130 is designed to prevent dust. In addition, in application, the design of the projection lens 100E2 shown in FIG. 13B can also be adopted. The difference is that the projection lens 100E2 translates the above-mentioned glass cover 170 to contact the concave mirror 130 and ensures that the two are closed. It opens on the side of the concave mirror 130. When the concave mirror 130 is cut, the concave mirror 130 may further include another glass cover 170A on the cut side of the opening to ensure that the dustproof effect is not affected. However, the present invention does not Not limited to this. The cutting of the concave mirror 130 and the design of the glass covers 170 and 170A described in FIGS. 13A and 13B can be freely applied to various embodiments.

In this embodiment, the actual design of each element of the projection lens 100E shown in FIG. 13A can be seen in Table 11 below. The interpretation method of the following table is the same as that of Table 1, and the repetitive parts will not be repeated.

Table 11 TL(mm)=237.2; EFL (mm)=2.2; TL/EFL=107.8; RF (mm)=26.7; IMH (mm)=8.945; RF/IMH=3.0; F/#=1.8; element surface Radius of curvature (mm) Spacing (mm) Refractive index (Nd) Abbe number (Vd) Clear aperture (RF) Concave mirror 130 S1 -19.66 45.55 75.2 Glass cover 170 S2 Unlimited 1.10 1.52 58.6 59.9 S3 Unlimited 10.11 58.5 Lens L1 S4 -19.27 11.78 1.50 81.5 10.4 Lens L2 S5 8.87 1.00 1.64 34.5 13.6 S6 36.25 0.20 16.1 Lens L3 S7 -81.46 6.47 1.49 70.2 19.0 S8 17.59 10.14 21.3 Lens L4 S9 36.87 8.00 1.53 56.3 30.3 S10 46.59 21.40 34.1 Lens L5 S11 -104.75 11.94 1.64 55.4 47.1 S12 50.53 0.20 48.0 Lens L6 S13 -18.64 12.60 1.53 56.3 42.9 S14 -9.78 26.55 31.2 Lens L7 S15 172.37 12.60 1.83 37.2 31.1 S16 50.19 2.12 32.3 Lens L8 S17 -164.92 5.63 1.50 81.5 30.2 S18 41.26 14.73 29.5 Aperture diaphragm 160 S19 Unlimited 4.24 11.6 Lens L9 S20 15.46 2.69 1.65 33.8 13.0 Lens L10 S21 -64.59 5.45 1.50 81.5 16.2 S22 16.07 0.20 18.0 Lens L11 S23 562.59 5.48 1.50 81.5 19.6 Lens L12 S24 17.19 1.03 1.76 27.5 20.4 S25 73.96 3.51 22.3 Lens L13 S26 -88.85 5.44 1.80 22.8 26.5 S27 42.06 2.09 27.1 Lens L14 S28 -59.86 4.95 1.51 64.0 26.7 S29 42.81 26.6 Transmissive smooth imaging device 60 S30 Unlimited 2.00 1.52 58.6 S31 Unlimited 3.20 稜鏡50 S32 Unlimited 16.00 1.73 28.3 S33 Unlimited 0.80 Glass cover 40 S34 Unlimited 1.10 1.51 62.9 S35 Unlimited 0.30

Please refer to Figure 13A and Table 11 at the same time. Among them, the lens L1 and the lens L2, the lens L9 and the lens L10, and the lens L11 and the lens L12 are compound lenses, such as double cemented lenses. Lens L4, lens L6, and lens L14 are aspheric lenses. In other words, the surface S1 of the concave mirror 130, the surface S9 and the surface S10 of the lens L4, the surface S13 and the surface S14 of the lens L6, and the surface S28 and the surface S29 of the lens L14 are aspherical surfaces. In addition, the rest of the optical characteristics and effects can be described with reference to the projection lens 100 in FIG. 1, and will not be repeated here.

Table 12 below lists the surface S1 of the concave mirror 130, the surface S9 and the surface S10 of the lens L4, the surface S13 and the surface S14 of the lens L6, the surface S28 and the surface S29 of the lens L14, the quadric coefficient values K and the aspheric coefficients AG of each order. .

Table 12 S1 S9 S10 S13 K -1.20 0 0 -1.34 A 5.28E-06 3.31E-05 5.28E-05 -1.16E-05 B -1.43E-08 -2.71E-07 1.54E-08 -7.46E-08 C 1.76E-11 7.85E-10 -3.15E-10 2.12E-10 D -1.64E-14 -6.57E-13 6.96E-13 -3.42E-13 E 9.46E-18 0 0 4.48E-16 F -3.01E-21 0 0 -2.29E-19 G 3.44E-25 0 0 0 S13 S28 S29 K -1.67 0 0 A -1.32E-04 2.09E-05 -7.69E-06 B 3.22E-08 2.81E-08 5.41E-08 C 9.67E-10 9.92E-11 -6.56E-11 D -1.49E-12 -7.91E-13 -4.97E-13 E 7.91E-16 0 0 F -1.06E-18 0 0 G 0 0 0

FIG. 14 is an imaging optical simulation data diagram of the projection lens according to the sixth embodiment of the present invention. Please refer to Figure 14. FIG. 14 is a graph of the optical transfer function (MTF) of the projection lens 100E. The interpretation method of FIG. 14 is the same as that of FIG. 3, and the repeated parts will not be repeated. It can be verified that the optical transfer function curve displayed by the projection lens 100E of this embodiment is within the standard range, so it has good optical imaging quality.

15 is a schematic cross-sectional view of a projection lens according to an eighth embodiment of the invention. Please refer to Figure 15. The projection lens 100F of this embodiment is similar to the projection lens 100A shown in FIG. 5. The difference between the two is that in this embodiment, the projection lens 100F further includes a mirror 180. The reflector 180 is disposed between the lens L5 and the lens L6 in the lens group 140 to bend the traveling direction of the light, but the present invention is not limited to this. In this way, the projection lens 100F can be adapted to different types of projectors, and the configuration of the mirror 180 can reduce the total length of the projection lens 100F.

The following table 13 is a list of parameters of each embodiment.

Table 13 TL (mm) EFL (mm) TL/EFL RF (mm) IMH (mm) RF/IMH The first embodiment 233.5 2.2 106.1 26.9 8.9 3.0 Second embodiment 233.5 2.2 106.1 25.5 8.9 2.9 The third embodiment 233.5 2.2 106.1 25.7 8.9 2.9 Fourth embodiment 233.5 2.2 106.1 25.5 8.9 2.9 Fifth embodiment 233.5 2.2 106.1 26.3 8.9 2.9 Sixth embodiment 237.2 2.2 107.8 26.7 8.9 3.0

In summary, in an embodiment of the present invention, the projection lens and the projector using the projection lens can allow the light beam emitted by the light valve to pass through the optical axis three times to produce three times of imaging. It has better optical quality under the requirement of chromatic aberration.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

10: Projector 20: Electronic device 30: Light valve 40, 170: glass cover 50: 稜鏡 60: Transmissive smooth image device 100, 100A, 100B, 100C, 100D, 100E, 100E2, 100F: projection lens 110: Reduced side 120: Magnified side 130: curved mirror 140, 150: lens group 160: aperture diaphragm 170, 170A: glass cover 180: Reflector A, A1, A2: Optical axis H: image height L: chief ray L1～L15: lens S1～S29: Surface

Fig. 1 is a schematic diagram of a projector according to a first embodiment of the present invention. 2 is a schematic cross-sectional view of the projection lens of the first embodiment of the invention. Fig. 3 is a schematic diagram of the light valve according to the first embodiment of the present invention. FIG. 4 is an imaging optical simulation data diagram of the projection lens according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a projection lens according to a second embodiment of the present invention. FIG. 6 is an imaging optical simulation data diagram of the projection lens according to the second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a projection lens according to a third embodiment of the present invention. FIG. 8 is an imaging optical simulation data diagram of the projection lens according to the third embodiment of the present invention. FIG. 9 is a schematic cross-sectional view of a projection lens according to a fourth embodiment of the present invention. FIG. 10 is an imaging optical simulation data diagram of the projection lens according to the fourth embodiment of the present invention. FIG. 11 is a schematic cross-sectional view of a projection lens according to a fifth embodiment of the present invention. FIG. 12 is an imaging optical simulation data diagram of the projection lens according to the fifth embodiment of the present invention. FIG. 13A is a schematic cross-sectional view of a projection lens according to a sixth embodiment of the invention. FIG. 13B is a schematic cross-sectional view of a projection lens according to a seventh embodiment of the invention. FIG. 14 is an imaging optical simulation data diagram of the projection lens according to the sixth embodiment of the present invention. 15 is a schematic cross-sectional view of a projection lens according to an eighth embodiment of the invention.

30: Light valve

40: glass cover

50: 稜鏡

60: Transmissive smooth image device

100: Projection lens

110: Reduced side

120: Magnified side

130: curved mirror

140, 150: lens group

160: aperture diaphragm

A: Optical axis

L: chief ray

L1~L13: lens

S1~S25: surface

Claims (24)

A projection lens includes, arranged in order from a reduced side to an enlarged side: A first lens, the first lens being the lens closest to the reduction side in the projection lens; A second lens, the outer diameter of the second lens is smaller than the outer diameter of the first lens; An aperture diaphragm; A third lens; A fourth lens; A fifth lens, the outer diameter of the fifth lens is greater than the outer diameter of the fourth lens; A sixth lens, the sixth lens is the lens closest to the magnification side in the projection lens, and the outer diameter of the sixth lens is smaller than the outer diameter of the fifth lens; and A concave mirror among them, When the projection lens is in focus, the positions of the first lens, the second lens, the aperture stop, and the third lens relative to the concave mirror are fixed, and the fourth lens can move along the optical axis relative to the concave mirror; and The number of lenses with refractive power in the projection lens is 9-30. The projection lens described in item 1 of the scope of patent application further includes: A first lens group including the first lens, the second lens and the third lens; and A second lens group includes the fourth lens, the fifth lens, and the sixth lens. A projection lens, including, arranged in order from a reduced side to an enlarged side: A first lens group, including a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side, the first lens being the first lens group The lens closest to the reduction side in the lens, the first lens is an aspheric lens, and the outer diameter of the first lens is larger than the outer diameter of the second lens; A second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in order from the reduction side to the magnification side, the fourth lens being the closest to the reduction in the second lens group Side lens, the sixth lens is the lens closest to the magnification side in the second lens group, and the outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens; and A concave mirror among them, When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move relative to the concave mirror along the optical axis; and The number of lenses with refractive power in the projection lens is 9-30. A projection lens, including, arranged in order from a reduced side to an enlarged side: A first lens group, including a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side, the first lens being the first lens group The lens closest to the reduction side in the lens, the first lens is an aspheric lens, and the outer diameter of the first lens is larger than the outer diameter of the second lens; A second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in order from the reduction side to the magnification side, the fourth lens being the closest to the reduction in the second lens group Side lens, the sixth lens is the lens closest to the magnification side in the second lens group, the outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens, the second lens group A reflector is included between the fourth lens and the sixth lens; and A concave mirror among them, When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move relative to the concave mirror along the optical axis; and The number of lenses with refractive power in the projection lens is 9-30. For the projection lens described in item 2, item 3 or item 4 of the scope of patent application, the first lens group and the second lens group are on the same optical axis. For the projection lens described in item 2, item 3, or item 4 of the scope of patent application, the number of lenses with refractive power in the second lens group is less than or equal to 15. According to the projection lens described in item 6 of the scope of patent application, the second lens group includes at least two aspheric lenses. The projection lens described in item 7 of the scope of patent application, wherein the projection lens is a fixed focus lens. For example, the projection lens described in item 1, item 3 or item 4 of the scope of patent application also includes: A seventh lens is located between the fifth lens and the sixth lens. The outer diameter of the seventh lens is smaller than the outer diameter of the fifth lens and larger than the outer diameter of the sixth lens. The fifth lens and the sixth lens There is no lens between the seven lenses, and there is a first intermediate image between the fifth lens and the seventh lens. The projection lens according to item 9 of the scope of patent application, wherein there is a second intermediate image between the sixth lens and the concave mirror. For example, the projection lens described in item 1, item 3 or item 4 of the scope of patent application also includes: A seventh lens is located between the fifth lens and the sixth lens. The outer diameter of the seventh lens is smaller than the outer diameter of the fifth lens and larger than the outer diameter of the sixth lens. The fifth lens and the sixth lens There is no lens between the seven lenses, and the light exit end of the fifth lens and the light entrance end of the seventh lens have non-telecentric characteristics. The projection lens described in item 2, item 3, or item 4 of the scope of patent application, wherein starting from the center of a first image surface on the reduction side, it reaches the center of a second image surface on the magnification side The beam of light passes through the optical axis of the first lens group, the second lens group or the concave mirror three times. The projection lens described in item 1, item 3, or item 4 of the scope of patent application, wherein TL is the distance from the surface of the first lens toward the reduction side to the concave mirror on the optical axis of the projection lens, and EFL is the effective focal length of the projection lens, which conforms to TL/EFL≧50. For the projection lens described in item 1, item 3 or item 4 of the scope of patent application, the reduced side of the projection lens has a telecentric characteristic. According to the projection lens described in item 2, item 3 or item 4 of the scope of patent application, the first lens group and the second lens group respectively include two double cemented lenses. A projector, including: A light source; A light valve, located downstream of the light path of the light source; A projection lens, which is arranged downstream of the light path of the light valve, includes, sequentially arranged from a reduced side to an enlarged side: A first lens group, including a first lens, a second lens, an aperture stop, and a third lens arranged in sequence from the reduction side to the magnification side, the first lens being the first lens group The outer diameter of the first lens is larger than the outer diameter of the second lens, and the outer diameter of the first lens is twice or more of an image height; A second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in order from the reduction side to the magnification side, the fourth lens being the closest to the reduction in the second lens group Side lens, the sixth lens is the lens closest to the magnification side in the second lens group, and the outer diameter of the fifth lens is larger than the outer diameters of the fourth lens and the sixth lens; and A concave mirror among them, When the projection lens is in focus, the position of the first lens group relative to the concave mirror is fixed, and the second lens group can move relative to the concave mirror along the optical axis; and The number of lenses with refractive power in the projection lens is 9-30. Such as the 16th projector in the scope of patent application, wherein the first lens group and the second lens group are on the same optical axis. For example, the projector of item 16 of the scope of patent application, wherein the projection lens is a fixed-focus lens, and the number of lenses with refractive power in the second lens group is less than or equal to 15 and includes at least two aspheric lenses. For example, the projector of item 16 of the scope of patent application, wherein the projection lens further includes a seventh lens located between the fifth lens and the sixth lens, and the outer diameter of the seventh lens is smaller than the outer diameter of the fifth lens And is larger than the outer diameter of the sixth lens, there is no lens between the fifth lens and the seventh lens, there is a first intermediate image between the fifth lens and the seventh lens, the sixth lens and the concave mirror There is a second intermediate image in between. For example, the projector of item 16 of the scope of patent application, wherein the projection lens further includes a seventh lens located between the fifth lens and the sixth lens, and the outer diameter of the seventh lens is smaller than the outer diameter of the fifth lens And is larger than the outer diameter of the sixth lens, there is no lens between the fifth lens and the seventh lens, and the light exit end of the fifth lens has a non-telecentric characteristic. For example, the projector of item 16 of the scope of patent application, in which the light beam starting from the center of a first image surface on the reduction side and reaching the center of a second image surface on the magnification side passes through the first lens The optical axis of the lens group, the second lens group, or the concave mirror is three times in total. For example, the 16th projector in the scope of patent application, wherein the projection lens conforms to TL/EFL≧50, where TL is the distance from the surface of the first lens facing the reduction side to the concave mirror on the optical axis of the projection lens, And EFL is the effective focal length of the projection lens. For example, the projector of item 16 of the scope of patent application, wherein the reduced side of the projection lens has a telecentric characteristic. For example, the projector of item 16 of the scope of patent application, wherein the first lens group and the second lens group respectively include two double cemented lenses.

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